As the communication technique becomes more popular, the volume of data (information volume) tackled by information processing apparatus, such as servers or routers, is increasing rapidly. On the other hand, the communication capacity required for transmitting signals among semiconductor devices including LSIs (Large Scale Integrated Circuits) composing the information processing apparatus is estimated to increase acutely in time to come.
Under these situations, a diversity of problems inherent in the electrical interconnection techniques used in communication employing electrical signals has come to the surface. These problems include increasing power consumption, increasing delay in signal transmission, deteriorated reliability in signal lines and interferences among electrical signals. To combat these situations, the use of optical interconnections to cope with variable distances for transmission ranging from long-distance transmission as in optical communication systems interconnecting base units down to the short-distance transmission within or among semiconductor devices or chips is being investigated carefully.
In Patent Literature 1, there is disclosed a semiconductor device in which field-effect transistors (FETs) and a semiconductor laser device are integrated on the front and back sides of one and the same substrate. In Patent Literatures 2, 3, there is shown an opto-electric complex module or an optical interconnection structure in which a light receiving element or a light receiver is surrounded by electrically conductive vias to interrupt stray light or electromagnetic noise to diminish the optical or electrical crosstalk.
In Patent literature 4, there is disclosed a structure in which a through-substrate via is formed in a region between a digital circuit and an analog circuit formed on a surface of a semiconductor substrate to suppress the electrical crosstalk.
In Patent Literature 5, a dummy plug formed of an electrically conductive material is embedded in an inner portion of a substrate to diminish the electrical crosstalk as well as to enhance thermal conductivity in a vertical direction.
[Patent Literature 1]
    JP patent Kokai Publication No. JP-S61-040081A (FIG. 1)[Patent Literature 2]    WO 2006/025523A1 (FIG. 1)[Patent Literature 3]    WO 2010/004850A1 (FIG. 1)[Patent Literature 4]    WO 2011/086612A1 (FIG. 1)[Patent Literature 5]    JP patent Kohyo Publication No. JP2013-522929A (FIG. 2)